DURA-ACE 9200 12 Speed Front Crankset 52-36 172.5mm with Power Meter: The Shimano Dura Ace FC-R9200 crank performs two crucial tasks: It converts pedal power into propulsion and ensures extremely fast and precise shifting. Not only do the lightweight crank arms, manufactured using Hollowtech II technology, contribute to this, but also the uniquely designed chainrings which feature a Hollowglide construction and ensure fast as well as smooth shifting. The result is responsive acceleration from any speed securing the 2x12-speed crankset an absolute top position. Compromise Power Meter When you want the best its only natural to gravitate towards the Shimano brand. This Shimano DURA-ACE FC-R9200-P dual-sided power meter has a reliable, integrated design. Being waterproof it brings all-weather reliability and is reliable for delivering precise information including left/right balance, cadence and much more. Technologies Hollowtech II - The guiding principle of Shimano's Hollowtech II technology is the perfect balance between stiffness, stability, weight and rotational efficiency. The goal was to produce a crank that minimises the effort required for the drive and enables more efficient power transmission. An exclusive forging process allows the production of extremely light crank arms that nevertheless guarantee maximum stiffness. The fixed connection of the right arm to the axle of the bottom bracket and its external bearing also serve an optimum relationship between stiffness and low weight.